Coalitional game theory for cooperative transmission in VANET: Internet access via fixed and mobile gateways

In Vehicular Ad-hoc Networks (VANETs), vehicles need to cooperate with each other or with a roadside infrastructure to transmit data. In this work, we study the cooperative transmission for VANETs using coalitional game theory. Each vehicle has a desire to access Internet via gateways that can be either fixed or mobiles. The gateways can enhance the vehicles’ transmissions by cooperatively relaying the vehicles’ data. Moreover, due to the mobility of the vehicles, we introduce the notion of encounter and predicted lifetime to indicate the availability of forwarding between the vehicle and gateway. We model the problem as a coalition formation game with non-transferable utility and we propose an algorithm for forming coalitions among the vehicles. To evaluate the proposed solution, we present and discuss the numerical results under two scenarios: fixed gateways scenario and mobile gateways scenario. The numerical results show that mobile gateways scenario is more effective than fixed gateways scenario in term of cooperative transmission. © Springer International Publishing Switzerland 2015.